1. Field of the Invention
The present invention relates to a fuel feeding apparatus for feeding a fuel to an internal combustion engine, and more particularly, to the fuel feeding apparatus having a liquid level detector for detecting a liquid level of the fuel in a fuel tank.
2. Description of Related Art
Japanese laid opened patent publication 356040/2001 discloses a conventional fuel feeding apparatus having a fuel tank cap body that is provided with a filter-equipped pump, that is, a fuel pump integrated with a fuel filter. The fuel tank cap body is also provided with a fuel gauge consisting of a liquid level detector utilizing a hall element, an arm unit extending from the liquid level detector, and a floating unit provided on the end of the arm unit.
The fuel gauge, however, because of the structure in which the floating unit is fixed to the end of the arm unit, requires enough space for the arm unit to move with a turning-radius corresponding to a depth of the tank, causing the apparatus to upsize in structure. In addition, the structure of the arm unit and the floating unit, which are formed to be adaptable to the shape of the tank, becomes complicated, resulting in difficulties in assembling the fuel feeding apparatus.
Further, because the fuel gauge needs a movable mechanism for the arm unit, the life of a bearing unit shortens due to the wear thereof.
Japanese laid opened patent publication 46626/2000 discloses another example of the fuel feeding apparatus. In this type, a floating unit of approximately circular cylindrical shape is secured to a frame member on which a strain gauge is provided, thereby the strain gauge detecting a strain created by buoyant force of the floating unit.
This type of the fuel feeding apparatus is simplified and downsized in the structure, but requires the frame member. In addition, since the strain gauge provided on the frame member is used in the state that the strain gauge is exposed to the fuel liquid or vapor, the sulfur contents of the fuel increase the contact resistance, causing a detected value to be deviated.